South Korea is set to transfer one KF-21 Boramae fighter prototype to Indonesia under a tentative agreement aimed at resolving financial disputes in their joint development program. The agreement, worth about 600 billion won ($406 million), covers a single-seat prototype along with related development expenses.
The aircraft, one of six test prototypes built by South Korea, has been used in various trials, including aerial refueling. The delivery schedule will be finalized once Indonesia settles its outstanding payments, expected by June.
The KF-21, South Korea’s first domestically developed supersonic fighter, was launched in 2015 as a joint project with Indonesia and is expected to conclude by mid-2026. Initially, Indonesia agreed to fund approximately 1.6 trillion won—around 20 percent of the total 8.1 trillion won program—in exchange for a prototype and access to key technologies.
Funding challenges emerged when Indonesia halted payments after contributing 227 billion won, resulting in the withdrawal of its engineers from the project. The country later proposed reducing its financial share to around 600 billion won, accompanied by a scaled-down technology transfer package, consistent with the revised plan to receive a single prototype.
The revised agreement was finalized in June 2025, with Indonesia having contributed about 500 billion won so far. The KF-21 program aims to replace South Korea’s F-4 and F-5 fighter fleets by 2030. The first prototype debuted in 2021 and completed its maiden flight in 2022. Production commenced in 2024, with the first production aircraft unveiled in March 2026 and operational deployment planned for September.
Despite earlier financial tensions, both countries reaffirmed their defense cooperation during a recent summit between South Korean President Lee Jae Myung and Indonesian President Prabowo Subianto. Discussions included collaboration on trainer aircraft and anti-tank missile systems. Indonesia is also reportedly negotiating the purchase of 16 KF-21 jets, which would mark South Korea’s first export sale of the aircraft if concluded.
